Jack, along with Team Bermuda, attacked Team Skull, defeating all of them and stealing their wristwatches, making them official participants in the Representative Battle of the Rainbow. During the third day of the Representative Battle, he, along with other two Vindices, appeared in front of Team Reborn andTeam Verde, fighting them. When the teams were able to damage the three Vindices' clothes, he praised them as the first people who are able to see their real appearances and that they have surpassed the power of human beings, even though only for a moment. When Reborn questioned why they have the pacifier similar to the Arcobaleno's, he replied that they cannot reveal anything without Bermuda's permission, leading Verde to think that Bermuda is affiliated with Checker Face. Hearing this, he shouted that Bermuda would never have allied himself with someone like Checker Face since he is worthy of being Arcobaleno. He stopped when the Vindice beside him told him not to reveal anything further, but he replied that it didn't matter if their opponents saw or heard them, since they were going to die either way.

Jack and the other two Vindices continued their attacks, knocking out Yamamoto, Gokudera, Ken, and Chikusa in the process. He proceeded to attack Mukuro and Tsuna, but Bermuda ordered him and his teammates to stop when Chrome arrived. After his two teammates were defeated by Mukuro and Chrome's combination attack, he attacks back and fights Tsuna. Tsuna, worried that his Boss watch might get destroyed, held back his power, causing Jack to be much at advantage. However, once Reborn convinced Tsuna to ignore the Boss watch, Tsuna no longer hesitated and defeated Jack by following in the same direction as the whirlwind created by Jack, destroying his battler watch.